ProofpointReviews of ipcheck.proofpoint.com

They are blocking completely trouble-free IP addresses not telling out their reasoning. There is an extortive business model behind the scenes. You have to be their customer to get your IP unblocked. Just google it ... It is a big shame that UPS (ups.com) uses their list to block incoming mail. We have just got blocked a perfectly innocent IP address. According to mxtoolbox.com, there is not a blacklist, other than Proofpoint, listing the IP address (checked over 80 blacklists). Reason not disclosed, no reply or reaction so far.

I don't know who these jokers are, but they have started blocking some of the emails that I send from my btinternet account. There is a link in their blocked email message which is useless. Their "chat" does not allow comments - all you get is "sales" or "I'm OK now" boxes to click.